TestFlaky: Allow Timeout for shared-worker-import-referrer.html

This CL adds Timeout in shared-worker-import-referrer.html expectation.
This test is currently flaky because of Timeout, and the similar issue
is happening as well in dedicated-worker-import-referrer.html.

I will continue the investigation about this issue, but we add Timeout
expectation for now.

Bug: 1049689
Change-Id: I891b80b51186d623c304ecb59a835f725f407a0e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2041374Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#739273}

third_party/blink/web_tests/TestExpectations

@@ -6609,6 +6609,9 @@ crbug.com/1048113 [ Debug ] virtual/threaded-prefer-compositing/fast/scroll-beha
 crbug.com/1048113 [ Debug ] virtual/threaded-prefer-compositing/fast/scroll-behavior/main-frame-scrollLeft.html [ Pass Failure ]
 crbug.com/1048113 [ Debug ] virtual/threaded-prefer-compositing/fast/scroll-behavior/subframe-interrupted-scroll.html [ Pass Failure ]
 
+crbug.com/1049689 external/wpt/workers/modules/shared-worker-import-referrer.html [ Pass Timeout ]
+crbug.com/1049689 virtual/omt-worker-fetch/external/wpt/workers/modules/shared-worker-import-referrer.html [ Pass Timeout ]
+
 # Swiftshader issue.
 crbug.com/1048149 external/wpt/html/browsers/the-window-object/apis-for-creating-and-navigating-browsing-contexts-by-name/open-features-non-integer-innerwidth.html [ Crash Timeout ]
 crbug.com/1048149 external/wpt/html/browsers/the-window-object/apis-for-creating-and-navigating-browsing-contexts-by-name/open-features-non-integer-screeny.html [ Crash Timeout ]